Mushroom named ‘Hokuto NT-100’

ABSTRACT

A new and distinct variety of mushroom, named Hokuto NT-100, is described, which mushroom has the following characteristics: large cap, thick meat, nice consistency, nice taste, uniform growth when cultivated in a facility, and suitable for bottle cultivation. The variety of mushroom named Hokuto NT-100 was developed from mushrooms related to Hokuto MY-95 and Hokuto MY-75, which are registered varieties of a Japanese corporation and a wild variety found in Aomori Prefecture of Japan.

BRIEF SUMMARY OF THE INVENTION

The present invention relates to a new and distinct variety of mushroom having the following characteristics: large cap, thick meat, nice consistency, nice taste, uniform growth when cultivated in a facility, and suitable for bottle cultivation. The new variety of mushroom named Hokuto NT-100 was developed from mushrooms related to Hokuto MY-95 and Hokuto MY-75, which are registered varieties of a Japanese corporation, and a wild variety found in Aomori Prefecture of Japan.

Latin name of genus and species and variety denomination of the claimed plant: The Latin name of the genus and species of ‘Hokuto NT-100 mushroom’ is Grifola frondosa (Dicks, ex Fr.) S. F. Gray, this mushroom is generally called “Maitake” in Japan and seems to be called “hen of the woods” in English.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top view of the Hokuto NT-100 mushroom;

FIG. 2 is an oblique view of the Hokuto NT-100 mushroom;

FIG. 3 is a partial side view of the Hokuto NT-100 mushroom;

FIG. 4 is an oblique view of the Hokuto NT-100 mushroom in bottle cultivation;

FIG. 5 is a side view of the Hokuto NT-100 mushroom in bottle cultivation;

FIG. 6 is a top view of the Hokuto NT-100 mushroom in outdoor cultivation;

FIG. 7 is a top view of the Hokuto MY-95 mushroom for the purposes of comparison;

FIG. 8 is a side view of the Hokuto MY-95 mushroom;

FIG. 9 is a top view of the Hokuto MY-95 mushroom in outdoor cultivation;

FIG. 10 is a top view of the MH18211 mushroom for the purposes of comparison;

FIG. 11 is a side view of the MH18211 mushroom;

FIG. 12 is a top of the MH18211 mushroom in outdoor cultivation, and

FIG. 13 is a chart showing the system which resulted in the Hokuto NT-100 mushroom.

DETAILED DESCRIPTION OF THE INVENTION

The history of the Hokuto NT-100 mushroom in terms of improvement period and the like are set forth in the following chronological list of each stage of variety improvement:

-   January 1993: By crossing MH18206 amd MH18215, the following three     fugal strains were obtained: Hokuto MY-75, Hokuto MY-95 and GD99. -   February 1995: Hyphae were obtained from Hokuto MY-75 and GD99. -   March 1995: By crossing the hyphae of Hokuto MY-75 and GD99,     MH182114 was obtained. -   May 1996: From Hokuto MY-95, hyphae were obtained. -   June 2000: From MH18284, hyphae were obtained. -   August 2000: By crossing the hyphae of MH18284 and MY-95, MH182113     was obtained. -   November 2000: From MH182114, hyphae were obtained. -   July 2001: From MH182113, hyphae were obtained. -   January 2002: By crossing the hyphae of MH182113 and MH182114, a     superior variety MH182115 was obtained. -   March 2002 to March 2003: Tests were repeated to identify the     characteristics of MH182115, and during this time, it was found that     bottle cultivation was favorable, and stability, uniformity and     differentiability were confirmed. In November 2002, MH182115 was     named Hokuto NT-100 and variety improvement was completed. More     tests were conducted after that, and characteristics tests were     completed in March 2003. The claimed cultivar is stable and     reproduces true to type in successive generations of asexual     reproduction.

The system which resulted in the Hokuto NT-100 mushroom is shown in the flow chart of FIG. 13.

The Hokuto NT-100 mushroom has the following characteristics: large cap, thick meat, nice consistency, nice taste, uniform growth when cultivated in a facility, and suitable for bottle cultivation.

The differences between the new variety and its parents are as follows:

The parent varieties are MH182113 and MH182114. Both the parent varieties; and the instant new variety of this application can be defined being different genetically because they show a positive reaction in a dual culture. The new variety is different from MH182113 in cultural characteristics in that the new variety can be yielded numerously and has a different cap color. The new variety differs from MH182114 in yield, cap color and number of cilia on the cap. The differences therebetween are summarized in the following table.

TABLE 1 Morphological Differences Instant New Variety MH182113 MH182114 Yield (grams) 547.1 350.0 787.8 Dark gray-brown Cilia on the cap Small Small Large

When Hokuto NT-100 was cultured with commercially available varieties, inhibition zones were seen. In addition, the optimal temperature for hyphal growth was approximately 24 degree C.

The morphological characteristics of Hokuto NT-100 are as follows: at the time of harvest, the cap is fan-shaped or circular; the margin is rounded off; hair is minimal; pore shape is elliptical (Type 1); and pore cross section is uneven. When naturally cultivated, the mode of development is medium and development occurs in September. Experimental data have also shown that the length of time from inoculation to development is 63 days; the optimal development temperatures is 18-20 degree C.; the optimal growth temperature is 17-18 degree C.; and yield is 547.2 g.

With regard to other characteristics, the vitamin D₂ content of Hokuto NT-100 was high at 20.6 mg/100 g (international units: 824 IU) according to experimental data.

Some of these characteristics tests for Hokuto NT-100 as compared to similar mushroom varieties Hokuto MY-95 and MH18211 (Mori Sangyo #51) are summarized in the following table:

TABLE 2 Characteristic code of filed variety Characteristics 01 02 03 04 05 Genetic Dual culture Dislike-touch reaction Physiology Mycelial growth Effect of temperature The optimum (° C.) 22 23 24 25 26 Growth rate 10° C. 15° C. 20° C. 25° C. 30° C. 35° C. Mycelial color white shape of the surface of smooth tough the colony Shape of colony edge regular colony thickness thin medium Density of hyphae sparse medium Cultivation characteristics Capsule formation little medium Capsule coloration Absent Length of time until <30 31˜ 41˜ 51˜ 61˜ fruit body fromation at 40 50 60 0 optimal temperature Development period (natural cultivation) Optimal development <15 15˜ 20˜ >25 temperature (C.) 20 29 Optimal fruit body <18 18˜ >21 growth temperature 21 (C.) Other Budding period (natural Early inter- cultivation) mediate Yield (g/bottle) Morphology Cap Size small medium Thickness Thin medium Notch Absent Cross sectional shape 1 2 3 Face color W G-W D-G B D-B Annulus 1 2 3 4 Hair fair medium Tube Shape of tube face 1 2 3 4 Unevenness of cross Absent sectional the tip of tube Tube position 1 2 3 Stipe shape 1 2 3 Characteristic code of filed variety Note Characteristics 06 07 08 09 (Data) Genetic Dual culture Dislike-touch reaction + − Physiology Mycelial growth Effect of temperature The optimum (° C.) 27 28 29 30 24° C. Growth rate 10° C. 0.8 15° C. 1.7 20° C. 2.4 25° C. 2.6 30° C. 1.0 35° C. 0.1 Mycelial color other white shape of the surface of other smooth the colony Shape of colony edge regular irregular colony thickness thick thick Density of hyphae dense sparse Cultivation characteristics Capsule formation much medium Capsule coloration present absent Length of time until >70 63 days fruit body fromation at optimal temperature Development period (natural 6 month cultivation) Optimal development 18˜20° C. temperature (C.) Optimal fruit body 17˜18° C. growth temperature (C.) Other Budding period (natural Late intermediate cultivation) Yield (g/bottle) 547.2 g Morphology Cap Size large 56.4 mm Thickness Thick 2.6 mm Notch present Absent Cross sectional shape type 2 Face color other dark Brown Annulus other type 3 Hair many few Tube Shape of tube face other type 1 Unevenness of cross present present sectional the tip of tube Tube position other type 3 Stipe shape other type 2 Code of the similar variety Hokuto MY- Characteristics 95 HM18211 Genetic Dual culture Dislike-touch reaction 09 09 Physiology Mycelial growth Effect of temperature The optimum (° C.) 04 05 Growth rate 10° C. 0.9 0.8 15° C. 1.4 1.8 20° C. 1.6 2.5 25° C. 2.0 2.9 30° C. 1.2 2.7 35° C. 0.1 0.2 Mycelial color 01 01 shape of the surface of 01 01 the colony Shape of colony edge 01 09 colony thickness 05 03 Density of hyphae 03 03 Cultivation characteristics Capsule formation 05 05 Capsule coloration 01 09 Length of time until 05 06 fruit body fromation at optimal temperature Development period (natural 6 month 7 month cultivation) Optimal development 02 02 temperature (C.) Optimal fruit body 01 01 growth temperature (C.) Other Buding period (natural 05 05 cultivation) Yield (g/bottle) 575.9 g 338.9 g Morphology Cap Size 07 07 Thickness 05 05 Notch 01 09 Cross sectional shape 02 02 Face color Grayish Grayish brown yellow Annulus 03 02 Hair 03 03 Tube Shape of tube face 02 01 Unevenness of cross 09 09 sectional the tip of tube Tube position 03 03 Stipe shape 02 01 The numbers used to describe the characteristics of the cross-sectional shape, annulus, shape of tube face and the others of the instant new variety are indicative of the morphological types prescribed in the Examination Standard stipulated officially in Japan. Distinguishable characteristics of Hokuto NT-100 are set forth in the following:

When cultured with Hokuto MY-95, an inhibition zone is seen. Hokuto NT-100 is different from Hokuto MY-95 in the following characteristics: optimal growth temperature is 24 and 26 degree C., respectively; meat thickness is thick and regular, respectively; yield is 547.2 and 575.9 g, respectively; cap surface color is dark red and grayish brown, respectively; and pore surface shape is type 1 and 2 prescribed in the Examination Standard officially stipulated in Japan, respectively. When cultured with MH18211, an inhibition zone is seen. Hokuto NT-100 is different from MH18211 in the following characteristics: optimal growth temperature is 24 and 28 degree C., respectively; margin shape is irregular and regular, respectively; meat thickness is thick and regular, respectively; bottom capsule is present and absent, respectively; length of time from inoculation to development is 63 and 73 days, respectively; length of time for natural development is 6 and 7 months, respectively; yield is 547.2 and 338.9 g, respectively; cap gill is present and absent, respectively; cap surface is color dark red and grayish yellow, respectively; annellation type is 3 and 2, respectively; and cross section shape of stipe is type 2 and 1, respectively.

The above comparative test results were based, at least in part, on the following tests where the cultivation conditions under which the above-mentioned characteristic tests were conducted were as follows:

-   -   a. Cultivation site: Nagano, Japan.     -   b. Cultivation period: March 2002 to March 2003.     -   c. Cultivation methods (location, facility, medium, cultivation         mode, scale, etc.). Mushrooms listed in the test results were         cultivated using conventional methods in a culture room with 300         containers and a growth room with 300 containers. In the         characteristics tests, cultivation was performed using ten bags         per block and the cultivation experiment was repeated twice.

-   The following tests were conducted:     -   -   ( 1 ) Dual culture.—Conducted according to the examination             standards for mushrooms where characteristics were observed             on Difco PDA medium. The strains used were: MH18211             Commercial strain (Mori Sangyo #51). MH182113 mating strain.             MH182114 mating strain. MH18284 Wild type. Hokuto MY-75.             Hokuto MY-95. MH18212 Commercial strain (Fujimoto sangyou             M10). MH18222 Commercial strain (Tochiokimaitake). MH148261             Commercial strain (Tokatiana). With regard to the             dislike-touch reaction, the results were as follows where +             is present and − is absent.

TABLE 3 Hokuto NT-100 Hokuto NT-100 − MH18211 + MH182113 + MH182114 + MH18284 + Hokuto MY-75 + Hokuto MY-95 + MH18212 + MH18222 + MH148261 +

-   -   -   ( 2 ) Mycelial growth.—The growth of Hokuto NT-100 was             compared with Hokuto MY-95 and MH18211.

TABLE 4 temperature (° C.) 10 15 20 25 30 35 Hokuto NT-100 (mm/day) 0.8 1.7 2.4 2.6 1.0 0.1 Hokuto MY-95 (mm-day) 0.9 1.4 1.6 2.0 1.2 0.1 MH18211 (min/day) 0.8 1.8 2.5 2.9 2.7 0.2

TABLE 5 temperature (° C.) 20 22 24 26 28 30 optimum temp. Hokuto NT-100 (mm/day) 2.3 2.5 2.6 2.5 2.1 1.3 24 Hokuto MY-95 (mm-day) 1.6 1.8 2.1 2.2 2.0 1.9 26 MH18211 (mm/day) 2.4 2.8 3.0 3.2 3.3 3.2 28

-   -   -   ( 3 ) Characteristics data.—Cultivation data for Hokuto             NT-100 was compared with Hokuto MY-95 and MH18211.

TABLE 6 Characteristics Hokuto NT-100 Hokuto MV-95 Capsule formation Medium Medium Capsule coloration Absent Absent Length of time until fruit body 60-63 days 60-63 days formation at optimal temperature Optimal development 18-21 C. 18-21 C. temperature Optimal fruit body growth 17-18 C. 17-18 C. temperature Development period (natural September September cultivation) Yield 574.2 ± 2.6 g 575.9 ± 53.8 g Cap size 56.4 ± 16.5 mm 43.6 ± 15.8 mm Cap thickness 2.6 ± 0.4 mm 2.6 ± 0.5 mm Cap surface color Dark yellowish red Grayish brown (1910) (1919) Characteristics MH18211 Capsule formation Medium Capsule coloration Present Length of time until fruit body 71-73 days formation at optimal temperature Optimal development 18-20 C. temperarure Optimal fruit body growth 17-18 C. temperature Development period (natural September cultivation) Yield 338.9 ± 44.7 g Cap size 45.1 ± 10.9 mm Cap thickness 2.6 ± 0.5 mm Cap surface color Grayish yellow (2212)

-   -   -   ( 4 ) Temperature data.—Data for the optimum development             temperature of Hokuto NT-100 was determined using             conventional cultivation methods where fungal development             was monitored at different temperatures, the results being             as follows:

TABLE 7 Primordium formation at each development temperature Development temperature (C.) Hokuto NT-100 <15 Primordium formation occurred 61 days after inoculation 16-20 Primordium formation occurred 56 days after inoculation 21-25 Low pigmentation on the culture medium surface >25 No budding As shown in Table 7, while primordium formation occurred at temperatures below 20° C., when considering cultivation style and productivity, earlier primordium formation is desirable. Therefore temperatures between 16 and 20° C. were suitable, and, in this temperature range, development was most favorable at 18-20° C.

(4) Vitamin D2 Content.

The vitamin D2 content in the fruit body was measured with HPLC and the results were as follows:

TABLE 8 Hokuto NT-100 Hokuto MY-95 HM18211 The vitamine D2(μg/100 g) 20.6 15.6 7.1 The vitamine D2(IU/100 g) 824.0 624.0 280.0

With regard to asexual reproduction of the subject mushroom:

-   -   (1) The fungal strains in question are preserved at 5° C. on         agar slant culture (agar medium) and continuously cultivated         once a year.     -   (2) The medium is a potato dextrose agar culture (PDA) made of         200 grams of potato, 20 grams of glucose, and 15 grams of agar         so as to have a pH value of 5.5 in 1 liter of distilled water.     -   (3) The cultivation of strains is carried out by picking out         mycelial fragment from the fungal strains preserved in (1)         mentioned above and put on the medium of (2). Then, the strains         are cultivated at about 25° C. for 14 days. After bacterial         threads of the strains preserved, the strains are displanted to         an incubation medium.

In a case of preserving the strains once again, the strains thus cultivated may be restored to the process (1) above.

The characteristic colors of parts of the instant new variety are recited herein based on Japan Color Standard for Horticultural Plant (JHS Color Chart). 

1. A new and distinct variety of mushroom, substantially as described and illustrated herein. 